1. Field of the Invention
The present invention relates to a display device having a display region surrounded by a seal member, and a manufacturing method thereof.
2. Description of the Related Art
In recent years, the demand for so-called thin display devices, such as liquid crystal display devices, has been rapidly growing. A liquid crystal display device has a pair of substrates and a liquid crystal layer provided between the substrates. The liquid crystal layer is usually surrounded by a seal member made of, for example, a thermosetting resin, and is thereby sealed between the pair of substrates. The seal member typically has an approximately rectangular frame shape. A display region that contributes to display is provided inside the seal member.
Japanese Laid-Open Patent Publication No. SHO 60-26321 discloses a seal member having a double structure in a flexible liquid crystal display device. In other words, an inner portion (the display region side) of the seal member is formed by a first seal portion, and a portion outside the first seal member is formed by a second seal portion. The first seal portion is made of a resin having low water permeability, and the second seal portion is made of a flexible resin.
Japanese Laid-Open Patent Publication No. 2002-277884 discloses a dam pattern that is formed between a seal member and a display region in order to prevent the seal member from flowing into the display region. The dam pattern hinders a flow of the seal member and the seal member is thus prevented from flowing into the display region.
As shown in FIG. 15, it is known in the art that, in a seal region 103 which is located outside a display region 101 and in which a seal member 102 is provided, photo spacers 104 having a dot pattern are dispersedly arranged on a substrate surface as in the display region 101. The photo spacers 104 have a square shape when viewed from above and each side of the square has a length of, for example, about 10 μm. The gap between a pair of substrates (cell gap) is kept constant by the photo spacers 104 in the seal region 103 and photo spacers (not shown) in the display region 101.
In the case of applying a seal member on a substrate by a dispenser or the like, it is difficult to accurately supply the seal member to a predetermined seal region where the seal member is supposed to be formed. If the seal member is supplied to a region inside the seal region on the display region side, the seal member may enter a liquid crystal layer, causing degradation in display quality. If the seal member is supplied to a region outside the seal region, on the other hand, reliable sealing cannot be obtained between a pair of substrates.